"High Occupancy Vehicle" lane, or car-pool lane. The
central concept for HOV lanes is to move more people
rather than more cars. Some HOV lanes carry almost half
of the people carried on the entire freeway. Regular
"mixed-flow" lanes are never converted to HOV lanes.
Rather, HOV lanes are always added to existing
facilities. Each vehicle that travels on an HOV lane
must carry the minimum number of people posted at the
entrance signs. Usually that means at least two people,
or in some cases three people. Each child counts as an
occupant, but pets, infants still in the womb,
inflatable dolls or ghosts do not (we've heard 'em all).
Violators are subject to a minimum $481 fine.
Exceptions: Motorcycles, even those carrying just one
person, are allowed to use the HOV lanes. Some HOV lanes
are in operation only during certain hours, which are
posted. Outside of those hours, they may be used by all
vehicles.